This application is for partial funding of a special symposium, entitled DNA Repair in Chromatin: The First 40 years (and Beyond), to be held May 21-23, 2015, at Washington State University, Pullman, WA. This symposium will occur on the 40th anniversary of the first published work in this field. Approximately 75 participants are expected to attend, and there will be a mix of individuals from younger scientists, relatively new to the field, to some of THE world leaders in the field over the past 40 years. Maintenance of genomic integrity is fundamental to life. The genome is under constant assault by endogenous metabolites and environmental sources that damage the DNA molecule, giving rise to heritable changes in the sequence of genes. DNA repair pathways are 'molecular guardians' of genomic integrity and are one of the first lines of defense against a wide range of human diseases, including spontaneous and environmentally induced cancers. DNA repair in eukaryotic cells takes place in the context of chromatin where DNA, including damaged DNA, is tightly packed into nucleosomes and higher order chromatin structures. Chromatin intrinsically restricts accessibility of DNA repair proteins to the damaged DNA and impacts the overall rate of DNA repair. This symposium will focus on the role of DNA packaging on mechanisms and signaling of DNA repair of chemically and physically induced DNA damage by environmentally relevant agents (e.g., UV radiation, alkylating agents, and reactive oxygen species). Each session will have three to five speakers and sufficient discussion time to allow for substantial audience participation. Furthermore, this symposium will bring together scientists from seemingly divergent interests (e.g., chromatin structure, molecular epidemiology and DNA repair) who should add significantly to its overall success. In addition, a poster session will be available toall participants, allowing for additional new findings to be presented and discussed.